This invention relates to electron spin resonance (ESR) spectrometers and more particularly to a portable electron spin resonance spectrometer which is dedicated to a limited range of applications.
Applications include, inter alia, immunoassay work as in determining antigen-antibody reaction, in determining the presence of drugs in body fluids; in determining the presence of certain contaminants in motor oil or other fluids; in tracing the underground flow of crude oil, in security systems wherein a card is impregnated with a spin labelled material, and in dating of archaeological finds. Currently there is a great volume of work being done to test blood or urine for the presence of drugs. it is expected that there will be increased use of ESR technology for security applications wherein a spin labelled material is sealed in a card like a credit card and an ESR sensor used to read the card to establish that the card carrier is to be admitted to a secured facility.
Electron spin resonance spectrometers are well known as laboratory devices, and in the form of research devices, typically incorporate magnets weighing a ton or more. Thus such devices are far too large and heavy to be reasonably portable. Some smaller bench top devices which have been available are also much too heavy to be readily transferred from an office or laboratory to the field for analytical work. There is, however, a need for an electron spin resonance spectrometer, or ESRS, which is readily portable and which can be carried to the field to do analysis of a specific and narrowly defined type. Such an ESRS should also be capable of being operated by field workers having minimal training. The usual large laboratory ESRS machines require technicians having a substantial level of training because of the nature of the instrumentation employed.